Using the histochemical analysis (Fluoro-Jade B and bis-benzimide 33342 Hoechst), the influence of nicotine on kainic acid (KA) induced hippocampal damage in 35-day-old Wistar male rats was studied. Kainic acid administration is a well established and relevant chemical model of temporal lobe epilepsy and from previous experiments it is known that nicotine is capable to diminish the severity of pathological phenomenons, accompanying KA administration. Unfortunately the protective dose of nicotine (1mg/kg) had significant side-effects (lost of posture control etc.), preventing the reasonable use of nicotine as a neuroprotectant. In this study we tried to administer nicotine in low doses (0.25 mg/kg) repeatedly (six times). According to the results obtained from histological analysis (using semi-quantitative grading scale), the fractionized administration of nicotine was able to decline the KA-induced damage significantly, moreover the nicotine side-effects were robustly decreased. Hence the repeated low-doses of nicotine seem to be more beneficial compared to the undivided high-dose administration.

The work has been supported by grants: GACR 305/09/P136, MSM 00216 208 16, GACR 309/09/0406.